Ly Dinh Vu, 37, Nguyen Chuong Dai, 25, and Hoang Van Tham, 33, have been identified as suspects in the dumping of oil into a creek last week, Nguyen Huu Duc, deputy police chief of Hoa Binh Province, said Friday.

Nguyen Chuong Dai (L) and Hoang Van Tham at the police station.
Photo courtesy of Hoa Binh Province police.

While Dai and Tham were arrested Thursday, the police are still on the hunt for Vu.

Dai and Tham told the police that on October 6, Vu hired them to drive a truck from Bac Ninh Province to the Thanh Ha brick and ceramic factory in Phu Tho Province in the north to collect and load the factory’s waste on to the truck.

On October 8, the three drove the truck and a car to Phu Minh Commune, Ky Son District of Hoa Binh Province to dump the oil and left the scene.

Whether Dai and Tham had been hired to dump the used oil into the environment as they said has not been ascertained.

Apart from hunting for Vu, police are continuing the investigation to identify others’ involvement in the case.

On Tuesday last week, a 2.5 ton tanker was seen dumping used oil into a creek in Hoa Binh Province that feeds into the Da River, which is sourced by the Vinaconex Water Supply Join Stock Company (Viwasupco) to process and supply clean water to around one million people in the southwestern part of Hanoi, about one eighth of the capital's population.

Black oil at a stream that feeds into the Da River in Hoa Binh Province,
which is sourced by Viwasupco to process and supply water to around
one million people in the southwestern part of Hanoi. Photo taken
on October 16, 2019 by VnExpress/Ba Do.

Two days later, Hanoi residents detected an unpleasant, pungent odor in their tap water. Tests of the smelly water by authorities later found that the level of styrene, an organic compound that is probably carcinogenic, was 1.3-3.6 times higher than normal.

Hanoi authorities then warned residents that they should not use the water for drinking or cooking, only for other purposes like washing clothes and bathing.

On Thursday, Viwasupco restored its water supply after a one-day suspension for cleaning its pipes and reservoirs. Hanoi officials Thursday said the latest tap water samples collected Monday passed safety tests, but continue to advise against drinking or cooking with it.

Meanwhile, oil cleanup at sections of the creek that feeds the Da River is continuing and could last until the weekend, workers said.

Viwasupco currently supplies 300,000 cubic meters of water per day.